Knitting-machine.



N0. 933,595. Patented Sept. 26, I899.

' W. H. KEHRER.

KNITTING-MACHINE.

(Application filed' Feb. 14, 1899.)

(No Model.)

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UNITED STATES PATENT OFFICEQ' VILLIAM H. KEHRER, OF DES MOINES, IOlVA.

KNITTING-MACHINE.

SPECIFICATION forming part of Letters Patent No. 633,595, dated September 26,1899.

Application filed February 14, 1899. Serial No. 705,486. No model.)

To (tZZ whom, it may concern.-

Be it known that LWILLIAM H. KEHRER, a citizen of the United States, residing at Des Moines, in the county of Polk and State of Iowa, have invented certain new and useful Improvements in Knitting-ltlachinespf which the following is a specification.

This invention relates particularly to stocking-knitting machines having a series of needleguiding cams designed to engage with shoulders formed upon the needles to move them vertically during their rotation with the inner cylinder. In all of such machines a certain number of cams are provided for the purpose of stopping the needles in their vertical movement byengaging with the said shoulders, so that as the machines are run at a comparatively high speed the needles will not be thrown upward too far. Heretofore the cams for this purpose-that is, stopping the upward movement of the needleshave been fixed to the outer cylinder, and when the rotation of the machine has reached a considerable speed the needles were thrown against the said fixed cam with such force as to frequently break the needles.

The object of my invention is to provide cams for this purpose so arranged that they will yield slightly under the impact of the needles in their upward movement, whereby the machine is made capable of rotation at a speed considerably greater than has been possible heretofore without breaking needles, it being understood that the said cams are arranged to yield only a suflicient degree to cushion the impact of the needle-shoulders, but not to permit the needles to pass upwardly beyond the desired limit.

My invention consists in the construction, arrangement, and combination, with a knitting-machine of this class, of one or more needle-guiding cams held in place by a yielding pressure device, whereby the objects contemplated are obtained, as hereinafter more fully set forth, pointed out in my claims, and illustrated in the accompanying drawings, in which- Figure 1 shows a vertical sectional view taken through the central portion of the circular frame of the knitting-machine, showin g the various needle-guiding cams. Fig. 2 shows a sectional view taken on the line 2 2 of Fig. 1. Fig. 3 shows a modified form of the needle-guiding cam.

Referring to the accompanying drawings, the reference-numeral 10 is used to indicate the cylindrical frame of the'knitting-machine, said frame being provided with a shoulder on its inner surface at 11 and with the beveled gear-teeth 12 at its base, whereby power is transmitted to rotate the said cylinder. At the rear of the frame 10.is an upwardly-pro jecting arm 13, having in its top a circular needle-guiding rim 14:. The numeral 15 indicates a collar which is fixed to a stationary support and which is connected with the frame 10 in such a manner that the frame may freely rotate within the said collar.

It is to be understood that the usual inner needle-bearing cylinder is inserted in the cylinder 10 and that needles having outwardlyproject-ed shoulders thereon are con nected with this inner cylinder, and such shoulders are arranged to rest upon the shoulder 11, before described. This shoulder 11 has one or more downwardly-inclined portions, such as 16, and the pivoted guide-cams 17 are connected with the frame 10 to enter said downwardly-inclined portions 16 of the shoulder 11.

All of the parts above described are of the kind now in general use.

It is to be understood in this connection that the shoulders of the needles above referred to travel on the top of the part 11 in a horizontal plane until they reach the pivoted cam 17. Then they are forced upwardly by said cam and travel upon its top surface until they pass beyond it. When at this point, they are directed, by means of the usual switch-cam, (not shown,) to the under surface of the opposite one of the cams 17. It is to be further remembered in this connection that all of the needles are in engagement with the yarn and that when they are drawn down by the cam, as just stated, the said yarn pulls upwardly upon them, thereby holding the shoulders of the needles firmly against the under surface of the cam 17 and drawing said cam to its upward limit. The shoulders of the needles never engage the surface 16 when in use.

When the needles have passed downwardly along the under edge of the cams 17 and then end 21.

move upwardly to a point beyond the end of the cam 17, it is obvious that if the machine is running at a high rate of speed the needles will be thrown upwardly with considerable force. It is of course necessary that the up ward movement of the needles stop at the end of the cam 17 and that they then move in a horizontal plane on top of the shoulder 11. To provide means whereby these needles may be thus stopped at this point and that without danger of breaking the needles, I have provided a cam 18 with a horizontal shoulder on its under side at 19 and with the surface 20 at one end extended parallel with the end of the cam l7 and also with an upturned This cam is arranged in a position directly over the end of the cam 17, so that the shoulders on the needles as they pass upwardly will strike on the under surface 19 of said cam. Two pins 22 are fixed to this cam 18, projected horizontally upward through the slots 23 in the frame 10. A reinforcing-block 24 is fixed to the outer surface of the part 10, and in this block are two vertical openings 25, extending from its top downwardly. The said pins 22 are passed through slots 26 in the block 24 adjacent to the opening 25, and a head 27 on the end of each pin is positioned within the opening 24 to be capable of a vertical movement therein. A coiled spring 28 is placed in the opening 25 above the head 27, and a disk 29 is fitted in the top of said opening. Hence the resiliency of the spring 28 will be exerted to hold the pins 22 to their downward limit. By this means it is obvious that when the shoulders of the needles strike the under surface of the cam 18 with great force the cam will yield slightly and move upwardly against the springs 28, and thereby cushion the impact of the shoulders against the cam sufficiently to prevent the needles from becoming broken.

In the modified form shown in Fig. 3 I have dispensed with a solid metal cam 18, mounted on springs, and have substituted therefor a cam the under surface of which is of substantially the same shape as that of the cam 18. However,this cam is composed of a single leaf-spring, (indicated by the numeral 30,) with its inner end securely fixed to the interior of the frame 10 by means of the screws 31 the other end being free to move vertically.

- This cam is arranged with relation to the cam 17 in such a manner that the impact of the needles will be received upon the under surface of the spring 30 at about its central portion-that is, a slight distance from the point where it is fixed to the frame lO-and the spring is made of such resiliency that it may yield slightly under the impact of the needles sire to beunderstood as limiting myself to the application of cams provided with a yielding pressure device for holding them in place to this particular point on knitting-machines, as it is obvious that the same principle may be readily applied to knitting-machines at any point where the direction of movement of the needles is abruptly changed, and hence the needles when the machine is rotated at a high speed will tend to fly beyond the path in which they are intended to move.

In practical use it is obvious that with a machine provided with my improved cams the rotation of the needles may be increased to a very great extent, and therefore the efficiency of the machines will be greatly in-.

creased, inasmuch as less time will be consumed in doing the same amount of work than heretofore.

I am aware that heretofore devices have been placed in the path of the needles of machines of this class and held by yielding pressure against the shanks of the needles with the intention of preventing their flying out of their proper path when the direction of their movement was alternately changed; but all of said devices merely engaged the shanks of the needles in such a manner as to operate as a drag. In use these devices have been found inefficient for the reason that when a Very high speed was attained the drag upon the needles would not be sufficient to successfully hold them to their proper path. In other words, the amount of drag on the needles being the same at all speeds of the machine it necessarily follows that when the speed varies the needles will take a somewhat different path under the different speeds of rotation.

In machines of the class in which the yarn normally exerts an upward pull upon the needles when they are below the normal level and this pull is relaxed as soon as they reach the normal level it is obvious that after the shoulders of the needles pass upward beyond the inclined side of the drawing-down cam there will be a tendency for them to fly, by reason of their momentum, upwardly above the guiding-surface. Hence heretofore very high speeds were impossible for the reason that the fixed cams that have been located heretofore at this point have tended to break the needles.

I am not aware that a cam having a flat surface against which the shoulders of a needle may strike has ever been placed at this point at the end of the upward movement of the needles in a knitting-machine and supported upon yielding pressure devices which would permit them to move vertically a slight degree and at the same time positively prevent the needles from passing upwardly beyond it.

I am aware, further, that heretofore switchcams have been located at various portions in the machine and mounted upon yielding pressure devices; but I am not aware that heretofore a guiding or directing cam has IIO been located at the point where the needles move upwardly and then turn into a horizontally-moving direction and that are mounted upon yielding pressure devices, so that as the said needles pass beyond the upwardly-inclined cam they may strike upon yielding surfaces, which change their direction to a horizontal movement, and thereby prevent breakage of the needles by cushioning the impact at this point.

Having thus described my invention, what I claim, and desire to secure by Letters Patent of the United States therefor, is

1. The combination with a cylindrical stocking-knitting machine having one or more drawing-down cams, of one or more directing or guiding cams yieldingly mounted and located directly over the ends of the upwardlyinclined portions of the drawing-down cams to permit the needles to strike upon their under surfaces and capable of a slight vertical movement so that when engaged by the needles running at a high rate of speed the said directing or guiding cams may move upwardly, for the purposes stated.

2. In a cylindrical stocking-knitting ma chine having one or more drawing-down cams,

the combination of one or more guiding-cams slidingly mounted for vertical movement directly over the upwardly-inclined portion of the drawing-down cams and arranged directly in the path of the needles after leaving the said upwardly-inclined surfaces of the drawing-down cams so that the needles will impinge the under surfaces of the guiding-cams and pass under them, pins connected with each of said guiding cams and projected through slots in the machine frame, and springs to force said pins downwardly so that the needles may pass under the said guidingcams and when the machine is rotated at high speed the impact of the needles upon the cams may force them upwardly in opposition to the pressure of the springs, substantially as and for the purposes stated.

WILLIAM H. KEHRER.

Witnesses:

F. G. STUART, J. RALPH ()RWIG. 

